Based on expectations of natural progression, the Patriots’ trio of starting linebackers should make even more of an impact in the upcoming season after their electric initial go-round. Jerod Mayo, Brandon Spikes and Dont’a Hightower grew up well together in 2012, and they provided enough reasons to believe the extra year of chemistry and collective knowledge will make a difference in 2013. Mayo, the captain, is especially looking forward to Hightower’s step forward in his second season. “Definitely, you always get better from Year 1 to Year 2, or hopefully you get better from Year 1 to Year 2,” Mayo said, while pausing to note that nothing is automatic. “You’re more comfortable. You know what to expect. Dont’a, he’s been here. He’s been working hard, and hopefully we’ll continue to grow as a unit.” Hightower, a first-round pick, instantly grasped the Patriots’ playbook due to its similarities to Nick Saban’s system at Alabama. The added confidence and comfort level with his teammates should help him just play and anticipate more than think and react. Mayo thought back to his rookie season in 2008 to relate to Hightower’s first year. “The biggest challenge for me was just the hours, but it was a welcome challenge,” Mayo said. “It’s better than being in study hall. I enjoy watching film, and if you love football, this is the place for you. Everyone around here loves to play football. They love the game. You go to some teams, or you see some players or you hear other players say they’re just doing it for a paycheck. But guys here, they genuinely love the game. The coaches love the game, and we’re all trying to get better.” Spikes broke out last season as much as any player on the team. His health was a big reason for his leap in consistency, and Spikes’ freewheeling, bruising on-field personality led to five forced fumbles, which was the second most among NFL linebackers.